Meenakshi Bancrjee*, Rachana Chouhan, Vidhi Verma & Shivani Gole
Laboratory of Algal Biotechnology, Department of Bioscience
Barkatullah University, Bhopal, 462026, (M.P)
Received 3rd May, 2008 ; Revised 21st August,2008
Abstract : The pollution of the environment with toxic heavy metals is a result of many human activities, such as mining and metallurgy, and the effects of these metals on the rice field ecosystems are of large economic and public health significance. The ability of cyanobacteria to selectively absorb various heavy metals ions have been recognized for over a decades. We have investigated the bioremediation of selenium by an active culture of cyanobacterium Hapalosiphon .sp. under aerobic and pHcontrolled culture conditions. Selenium was supplied as selenium dioxide (SeO2) in concentrations ranging from I μg/ml to 400 μg/ml and sublethal and lethal concentration of the organisms for the selenium was found to be 200 μg/ml and 250 μg/ml respectively. The growth and nitrate reductase activity of Hapalosiphon sp. were comparatively studied in all experimental sets (control, sublethal and lethal) though a time course study till 120 hour. The study revealed that the growth was reduced in sublethal and lethal concentration compared to control. But maximum nitrate reductase activity was obtained in sublethal concentration compared to control and lethal. We conclude that presence of Selenium in any ecological niche with cyanobacteria will not affect the nitrogen economy of that ecosystem.